: The overall aim of this project is to develop and exploit a system whereby a specific cellular target protein or proteins can be destroyed by the proteasome on command. The proposed work will facilitate the development of a biotechnology through which both important elements of protein expression, synthesis, and degradation can be addressed effectively. The investigators propose to utilize protein modules that normally direct regulated degradation of ornithine decarboxylase (ODC), by delivering them to targets of choice. The two critical components are the C terminus of ODC (CODC) and a portion of the N terminus of antizyme (NAZ). They will use as a conveniently assayed target the enhanced green fluorescent protein (EGFP). They will test the feasibility of this approach by using a means of conditional association of two fusion proteins, containing FKBP12 and FRB domains, that depends on the drug rapamycin. Both in vitro and in vivo degradation (in cultured cells) will be tested. First, they will determine whether FRB-EGFP-CODC is degraded when bound to NAZ-FKBP12. Second, they will determine whether induced translational frameshifting can be used to modulate the activity of this process. Third, they will determine whether CODC can also be used as a conditional degradation signal. PROPOSED COMMERCIAL APPLICATION: NOT AVAILABLE